Spark-plug.



A. SCHMIDT.

- SPARK PLUG.

APPLICATION man on. Is. 1913.

' 1,138,797, Patented May 11, 1915.

WWW/mm nNrrnD s'rai'rns PATENT mm ALBERT "SCHMIDT,

0F FLINT, MICHIGAN, A

or FLINT, MICHIGAN,'ASSIGNOR 'ro CHAMPION IGNITION COMPANY,

CORPORATION or MICHIGAN.

SPARK-PLUG.

T all whom it may concern Be' it known that I, ALBERT SoHMrD'r, a citizen'oi' the Republic of France, residing at Flint, in the county of Greneseeand Stateof Michigan, have invented'certain new and useful Improvements in Spark-Plugs, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to spark plugs and particularly to the construction of the grounded electrode and manner of mounting the same as hereinafter set forth.

In the drawings: Figure l is a perspective View of a portion of a spark plug, showing my improved construction of electrode applied thereto; Fig. 2 is a section through a portion of the plug casing with the detached electrode ready for engagement therewith; and Fig; 3 is an enlarged cross section showing the manner of securing the electrode.

It is the primary object of the invention "to obtain-a construction of grounded electrode which is inexpensive to manufacture, may lie-readily attached to the plug casing, will rapidly dissipate the heat generated at the sparking point, and is easily adjusted for'proper spacing of the spark gap. To this and the electrode A is preferably formed *ei' a stamping from sheet metal,

having the hooked or return-bent end B for .extending into. proximity to the cooperating electrode, and the widened shank-C for attachment to the plug-casing D. The method of. attachment employed is,

slot E in the Wall of the plug, which is of a width to receive the thickness of the shank.

The shank portionC is then inserted in this slot, being of a width to project beyond the 40 opposite ends thereof, and is then secured by pinching or upsetting the projecting portions, as shown in Fig. 3. This results in expanding the metal within the slot .so .as to press the opposite surfaces" thereof in close contact With the contacting surfaces of the slot, thereby not only securel fastening the electrode in position, but

Specification Of Letters Patent.

sipated through the en .spacing of the spark gap,

first, to cut a lso obtaining Patented-May 11, 1915.

Application filed October 13, 1913. Serial NO. 794,972.

' good heat conduction. As a result, the heat generated by the spark willbe rapidly dislarging section of the electrode until'it reaches the upset shank, from which it will pass through tlfe contactir g Walls and .the slot into the plug-casing; The electrode isalso one which permits of being readily adjusted for proper or hook portion B may be easily bent. That-I claim as my invention is:

l. A spark'plug, comprising a plug-casing having a transverse, slot in the inner end wall thereof, and

from sheet metal inserted in said slot and projecting beyond the sides thereof, the projecting portions beingupset. to expand'the' metal in the slot into heat-conducting contact with the casing.

:2. In a spark plug, a plug-casing having a transversely-extending slot in the inner end wall thereof, and an electrode formed of sheet metal having a shank portion inserted in said slot-and expanded to form a retaining and heatconducting connection.

3. In a spark plug, the combination of a. plug-casing having a transversely-extending slot in the inner end wall thereof, and an electrode of hooked or return-bent form having an enlarged shank and tapering toward the point, said -shank being inserted in said slot to project beyond the opposite sides thereof and being upset to-form a retaining and heat-conducting connection.

4:. In a spark plug, a plug casing having a transverse slot in the inner end Wall thereof, and an electrode formed of sheet metal having a shank portion inserted in said slot and extending longitudinally from said wall andiexpanded to form a retaining and heatconducting connection. r

In testimony whereof I afiix my signature ALICE SWEETWOOD.

as the return-bent .an electrode fashioned. 

